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Additive Lie (ξ-Lie) Derivations and Generalized Lie (ξ-Lie) Derivations on Prime Algebras

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Acta Mathematica Sinica,English Series 2013年第2期29卷 383-392页

作者： xiao fei QI Jin Chuan HOU Department of Mathematics Shanxi University Department of Mathematics Taiyuan University of Technology

The additive （generalized） ξ-Lie derivations on prime algebras are characterized. It is shown, under some suitable assumptions, that an additive map L is an additive generalized Lie derivation if and only if it is the sum of an additive generalized derivation and an additive map from the algebra into its center vanishing all commutators; is an additive （generalized） E-Lie derivation with ξ -if and only if it is an additive （generalized） derivation satisfying L（ξA） =- ξL（A） for all A. These results are then used to characterize additive （generalized） ξ-Lie derivations on several operator Mgebras such as Banach space standard operator algebras and yon Neumman algebras.

关键词： Prime algebras ξ-Lie derivations generalized ξ-Lie derivations

Predictability of Chinese Summer Extreme Rainfall Based on Arctic Sea Ice and Tropical Sea Surface Temperature

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Journal of Ocean University of China 2019年第3期18卷 626-632页

作者： ZHU Zhihui HUANG fei XIE xiao Shanghai Marine Meteorological Center Shanghai 201306 China Key Laboratory of Physical Oceanography Ocean University of China Qingdao 266100 China Ningbo Collaborative Innovation Center of Nonlinear Harzard System of Ocean and Atmosphere Ningbo University Ningbo 315211 China

Chinese summer extreme rainfall often brings huge economic losses, so the prediction of summer extreme rainfall is necessary. This study focuses on the predictability of the leading mode of Chinese summer extreme rainfall from empirical orthogonal function(EOF) analysis. The predictors used in this study are Arctic sea ice concentration(ASIC) and regional sea surface temperature(SST) in selected optimal time periods. The most important role that Arctic sea ice(ASI) plays in the appearance of EOF1 may be strengthening the high pressure over North China, thereby preventing water vapor from going north. The contribution of SST is mainly at low latitudes and characterized by a significant cyclone anomaly over South China. The forecast models using predictor ASIC(PA), SST(PS), and the two together(PAS) are established by using data from 1980 to 2004. An independent forecast is made for the last 11 years(2005-2015). The correlation coefficient(COR) skills between the observed and cross-validation reforecast principal components(PC) of the PA, PS, and PAS models are 0.47, 0.66, and 0.76, respectively. These values indicate that SST is a major cause of Chinese summer extreme rainfall during 1980-2004. The COR skill of the PA model during the independent forecast period of 2004-2015 is 0.7, which is significantly higher than those of the PS and PAS models. Thus, the main factor influencing Chinese summer extreme rainfall in recent years has changed from low latitudes to high latitudes. The impact of ASI on Chinese summer extreme rainfall is becoming increasingly significant.

关键词： ASI summer extreme rainfall prediction

Arctic sea ice in CMIP5 climate model projections and their seasonal variability

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Acta Oceanologica Sinica 2017年第8期36卷 1-8页

作者： HUANG fei ZHOU xiao WANG Hong Physical Oceanography Laboratory/CIMST Ocean University of ChinaQingdao 266100China Qingdao National Laboratory for Marine Science and Technology Qingdao 266200China Ningbo Collabrative Innovation Center of Nonlinear Harzard System of Ocean and Atmosphere Ningbo UniversityNingbo 315211China

This paper is focused on the seasonality change of Arctic sea ice extent （SIE） from 1979 to 2100 using newly available simulations from the Coupled Model Intercomparison Project Phase 5 （CMIP5）. A new approach to compare the simulation metric of Arctic SIE between observation and 31 CMIP5 models was established. The approach is based on four factors including the climatological average, linear trend of SIE, span of melting season and annual range of SIE. It is more objective and can be popularized to other comparison of models. Six good models （GFDL-CM3, CESM1-BGC, MPI-ESM-LR, ACCESS-1.0, HadGEM2-CC, and HadGEM2-AO in turn） are found which meet the criterion closely based on above approach. Based on ensemble mean of the six models, we found that the Arctic sea ice will continue declining in each season and firstly drop below 1 million km2 （defined as the ice-free state） in September 2065 under RCP4.5 scenario and in September 2053 under RCP8.5 scenario. We also study the seasonal cycle of the Arctic SIE and find out the duration of Arctic summer （melting season） will increase by about I00 days under RCP4.5 scenario and about 200 days under RCPS.5 scenario relative to current circumstance by the end of the 21st century. Asymmetry of the Arctic SIE seasonal cycle with later freezing in fall and early melting in spring, would be more apparent in the future when the Arctic climate approaches to ＂tipping point＂, or when the ice-free Arctic Ocean appears. Annual range of SIE （seasonal melting ice extent） will increase almost linearly in the near future 30-40 years before the Arctic appears ice-free ocean, indicating the more ice melting in summer, the more ice freezing in winter, which may cause more extreme weather events in both winter and summer in the future years.

关键词： Arctic sea ice CMIP5 seasonal cycle melting season annual range

Reutilize tire in microbial fuel cell for enhancing the nitrogen removal of the anammox process coupled with iron-carbon micro-electrolysis

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Frontiers of Environmental Science & Engineering 2021年第6期15卷 319-330页

作者： fei Xie Bowei Zhao Ying Cui xiao Ma xiao Zhang Xiuping Yue College of Environmental Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China

In this study,microbial fuel cells(MFCs)were explored to promote the nitrogen removal performance of combined anaerobic ammonium oxidation(anammox)and Fe-C micro-electrolysis(CAE)*** average total nitrogen(TN)removal efficiency of the modified MFC system was 85.00%,while that of the anammox system was 62.16%.Additionally,the effective operation time of this system increased from six(CAE system alone)to over 50 days,significantly promoting TN *** enhanced performance could be attributed to the electron transferred from the anode to the cathode,which aided in reducing nitrate/nitrite in *** H+released through the proton exchange membrane caused a decrease in the pH,facilitating Fe *** pyrolyzed waste tire used as the cathode could immobilize microorganisms,enhance electron transport,and produce a natural Fe-C micro-electrolysis *** to the microbial community analysis,Candidatus kuenenia was the major genus involved in the anammox ***,the SM1A02 genus exhibited the highest abundance and was enriched the fastest,and could be a novel potential strain that aids the anammox process.

关键词： Waste tire MFCs Micro-electrolysis Anammox Feammox

Involvement of phosphatidate phosphatase in the biosynthesis of triacylglycerols in Chlamydomonas reinhardtii

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2013年第12期14卷 1121-1131页

作者： xiao-dong DENG Jia-jia CAI xiao-wen fei Key Laboratory of Tropical Crop Biotechnology Ministry of Agriculture Institute of Tropical Bioscience and Biotechnology Chinese Academy of Tropical Agricultural Sciences School of Science Hainan Medical College

Lipid biosynthesis is essential for eukaryotic cells, but the mechanisms of the process in microalgae remain poorly understood. Phosphatidic acid phosphohydrolase or 3-sn-phosphatidate phosphohydrolase(PAP) catalyzes the dephosphorylation of phosphatidic acid to form diacylglycerols and inorganic orthophosphates. This reaction is integral in the synthesis of triacylglycerols. In this study, the mRNA level of the PAP isoform CrPAP2 in a species of Chlamydomonas was found to increase in nitrogen-free conditions. Silencing of the CrPAP2 gene using RNA interference resulted in the decline of lipid content by 2.4%–17.4%. By contrast, over-expression of the CrPAP2 gene resulted in an increase in lipid content by 7.5%–21.8%. These observations indicate that regulation of the CrPAP2 gene can control the lipid content of the algal cells. In vitro CrPAP2 enzyme activity assay indicated that the cloned CrPAP2 gene exhibited biological activities.

关键词： Phosphatidate phosphohydrolase 2 Triacylglycerol biosynthesis RNAi Chlamydomonas reinhardtii Nitrogen deprivation Over-expression

A COMPARATIVE STUDY OF DATA MINING METHODS IN CONSUMER LOANS CREDIT SCORING MANAGEMENT

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Journal of Systems Science and Systems Engineering 2006年第4期15卷 419-435页

作者： Wenbing xiao Qian ZHAO Qi fei Institute of Systems Engineering Huazhong University of Science & Technology Wuhan 430074 China School of Economics Renmin University of China Beijing 100872 China

Credit scoring has become a critical and challenging management science issue as the credit industry has been facing stiffer competition in recent years. Many classification methods have been suggested to tackle this problem in the literature. In this paper, we investigate the performance of various credit scoring models and the corresponding credit risk cost for three real-life credit scoring data sets. Besides the well-known classification algorithms （e.g. linear discriminant analysis, logistic regression, neural networks and k-nearest neighbor）, we also investigate the suitability and performance of some recently proposed, advanced data mining techniques such as support vector machines （SVMs）, classification and regression tree （CART）, and multivariate adaptive regression splines （MARS）. The performance is assessed by using the classification accuracy and cost of credit scoring errors. The experiment results show that SVM, MARS, logistic regression and neural networks yield a very good performance. However, CART and MARS＇s explanatory capability outperforms the other methods.

关键词： Data mining credit scoring classification and regression tree support vector machines,multivariate adaptive regression splines credit-risk evaluation

On the transient models of the VITAS code:applications to the C5G7-TD pin-resolved benchmark problem

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Nuclear Science and Techniques 2023年第2期34卷 28-57页

作者： Wei xiao Han Yin xiao‑Jing Liu Hui He Teng‑fei Zhang School of Nuclear Science and Engineering Shanghai Jiao Tong UniversityShanghai 2002040China

This article describes the transient models of the neutronics code VITAS that are used for solving time-dependent,pinresolved neutron transport *** uses the stiffness confinement method(SCM)for temporal discretization to transform the transient equation into the corresponding transient eigenvalue problem(TEVP).To solve the pin-resolved TEVP,VITAS uses a heterogeneous variational nodal method(VNM).The spatial flux is approximated at each Cartesian node using finite elements in the x-y plane and orthogonal polynomials along the *** discretization utilizes the even-parity integral approach at the nodes and spherical harmonic expansions at the *** further lower the computational cost,a predictor–corrector quasi-static SCM(PCQ-SCM)was *** the VNM framework,computational models for the adjoint neutron flux and kinetic parameters are *** direct-SCM and PCQ-SCM were implemented in VITAS and verified using the two-dimensional(2D)and three-dimensional(3D)exercises on the OECD/NEA C5G7-TD *** the 2D and 3D problems,the discrepancy between the direct-SCM solver’s results and those reported by MPACT and PANDAS-MOC was under 0.97%and 1.57%,*** addition,numerical studies comparing the PCQ-SCM solver to the direct-SCM solver demonstrated that the PCQ-SCM enabled substantially larger time steps,thereby reducing the computational cost 100-fold,without compromising numerical accuracy.

关键词： Stiffness confinement method Quasi-static method C5G7-TD benchmark Pin-resolved transient analysis

Axial acoustic radiation force on an elastic spherical shell near an impedance boundary for zero-order quasi-Bessel-Gauss beam

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Chinese Physics B 2021年第4期30卷 305-318页

作者： Yu-Chen zang Wei-Jun Lin Chang Su Peng-fei Wu Institute of Acoustics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Shell structures have increasingly widespread applications in biomedical ultrasound fields such as contrast agents and drug delivery,which requires the precise prediction of the acoustic radiation force under various circumstances to improve the system *** acoustic radiation force exerted by a zero-order quasi-Bessel-Gauss beam on an elastic spherical shell near an impedance boundary is theoretically and numerically studied in this *** means of the finite series method and the image theory,a zero-order quasi-Bessel-Gauss beam is expanded in terms of spherical harmonic functions,and the exact solution of the acoustic radiation force is derived based on the acoustic scattering *** acoustic radiation force function,which represents the radiation force per unit energy density and per unit cross-sectional surface,is especially *** simulated results for a polymethyl methacrylate shell and an aluminum shell are provided to illustrate the behavior of acoustic radiation force in this *** simulated results show the oscillatory property and the negative radiation force caused by the impedance *** appropriate relative thickness of the shell can generate sharp peaks for a polymethyl methacrylate *** radiation force can be obtained at small half-cone angles and the beam waist only affects the results at high *** that the quasi-Bessel-Gauss beam possesses both the energy focusing property and the non-diffracting advantage,this study is expected to be useful in the development of acoustic tweezers,contrast agent micro-shells,and drug delivery applications.

关键词： acoustic radiation force zero-order quasi-Bessel-Gauss beam impedance boundary elastic spherical shell

Microstructure and tensile properties of isothermally forged Ni–43Ti–4Al–2Nb–2Hf alloy

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Rare Metals 2013年第5期32卷 475-479页

作者： xiao-Yun Song Yan Li fei Zhang State Key Laboratory of Nonferrous Metals & Processes General Research Institute for Nonferrous Metals Key Laboratory of Aerospace Materials and Performance (Ministry of Education) Beijing University of Aeronautics and Astronautics

NiTi-Al-based alloys are promising high-tem- perature structural materials for aerospace and astronautics applications. A new NiTi-Al-based alloy Ni--43Ti-4AI- 2Nb-2Hf （at%） was processed via isothermal forging. The microstructure and mechanical properties at room temperature and high temperature were investigated through scanning electron microscope （SEM）, X-ray diffraction （XRD）, and tensile tests. Results show that the micro- structure of as-forged Ni-43Ti--4AI-2Nb-2Hf alloy con- sists of NiTi matrix, Ti2Ni phase, and Hf-rich phase. The simultaneous addition of Nb and Hf, which have strong affinities for Ti sites, promotes the precipitation of Hf-rich phases along the grain boundaries. The tensile strengths of Ni-43Ti-4A1-2Nb-2Hf alloy are dramatically increased compared with the ternary Ni-46Ti-4A1 alloy. At room temperature and 650℃, the yield stress of Ni--43Ti-4Al- 2Nb-2Hf alloy reaches 1,070 and 610 MPa, respectively, which are 30 % and 150 % higher than those of Ni--46Ti- 4Al alloy. The improved tensile property results from the solid solution strengthening by Nb and Hf, as well as the dispersion hardening of the Ti2Ni and Hf-rich phases.

关键词： Intermetallics NiTi-Al alloy Isothermal forging Tensile property Microstructure